JP2019131637A - Lubricant composition, manufacturing method of lubricant composition and non-stage transmission - Google Patents

Abstract

To provide the lubricant composition, the manufacturing method of the lubricant composition and the non-stage transmission using the lubricant composition, wherein the lubricant composition can achieve both a high traction coefficient and excellent low-temperature fluidity at higher levels, and has a high flash point.SOLUTION: The lubricant composition comprises a naphthenic synthetic oil (a) having a flash point of 140°C or higher and a branched ester (b) having 5 to 32 carbon atoms, the manufacturing method comprises manufacturing the lubricant composition, and the non-stage transmission comprises using the lubricant composition, wherein a content of the naphthenic synthetic oil (a) based on a total amount of the composition is 35 mass% or more to less than 80 mass%.SELECTED DRAWING: None

Description

  The present invention relates to a lubricating oil composition, a method for producing a lubricating oil composition, and a continuously variable transmission.

  Continuously variable transmissions, especially traction drive type transmissions, are smaller and lighter than gear-type transmissions, and can change gears without contact between metals, making them less susceptible to noise. doing. For this reason, application of traction drive type transmissions is being studied, particularly for electric vehicles.

  Lubricating oil compositions used in traction drive transmissions include, for example, North America and Northern Europe, together with a high traction coefficient under high temperature conditions (for example, about 120 ° C. for automobile applications) from the viewpoint of securing a large torque transmission capacity. In order to ensure low temperature startability in cold regions, low temperature fluidity is required such that the viscosity is low even under low temperature conditions (for example, about −40 ° C.). Is difficult. As a lubricating oil composition having such a performance, a lubricating base oil composition comprising a predetermined content of a naphthenic synthetic lubricating base oil and a paraffinic synthetic lubricating base oil having a predetermined flash point, A lubricating base oil composition containing an α-olefin has been proposed (for example, Patent Document 1).

JP 2000-204386 A

  In recent years, the required performance such as high traction coefficient and low-temperature fluidity for lubricating oil compositions used for continuously variable transmissions for automobiles, in particular, traction drive type transmissions, has become increasingly severe. The number of cases where the oil composition cannot cope is increasing. Further, in addition to performance such as a high traction coefficient and low temperature fluidity, a high flash point, for example, a flash point of 140 ° C. or higher, is required from the viewpoint of handling safety.

  The present invention has been made in view of the above circumstances, and has a high traction coefficient and excellent low-temperature fluidity at a higher level, and a lubricating oil composition having a high flash point. It is an object of the present invention to provide a manufacturing method and a continuously variable transmission using the lubricating oil composition.

  As a result of intensive studies in view of the above problems, the inventor has obtained a lubricating oil composition in which a predetermined naphthenic synthetic oil and an ester are combined at a predetermined content, that is, a naphthenic synthetic having a flash point of 140 ° C. or higher. Lubricant comprising an oil (a) and a C5-C32 ester (b) having a branched chain, and the content of the naphthenic synthetic oil (a) based on the total composition is 35% by mass or more and less than 80% by mass It discovered that the said subject could be solved with an oil composition.

  According to the present invention, a high traction coefficient and excellent low temperature fluidity can be achieved at a higher level, and a lubricating oil composition having a high flash point, a method for producing the lubricating oil composition, and the lubricating oil composition A continuously variable transmission using the can be provided.

  Hereinafter, an embodiment of the present invention (hereinafter simply referred to as “this embodiment”) will be described. In addition, in this specification, the numerical value concerning "above", "below", and "-" regarding description of a numerical range is a numerical value which can be combined arbitrarily.

[Lubricating oil composition]
The lubricating oil composition of the present embodiment includes a naphthenic synthetic oil (a) having a flash point of 140 ° C. or more and a C5-C32 ester (b) having a branched chain, and the naphthenic synthetic oil (a). The content based on the total amount of the composition is 35% by mass or more and less than 80% by mass. Hereinafter, each component which the lubricating oil composition of this embodiment may contain is demonstrated concretely.

(Naphthenic synthetic oil (a))
The lubricating oil composition of the present embodiment contains a naphthenic synthetic oil (a) having a flash point of 140 ° C. or higher (hereinafter sometimes referred to as “naphthenic synthetic oil (a)”) based on the total amount of the composition. The amount is required to be 35% by mass or more and less than 80% by mass. In the lubricating oil composition of the present embodiment, if the content of the naphthenic synthetic oil (a) based on the total composition is not 35% by mass or more and less than 80% by mass, the high traction coefficient and the excellent low-temperature fluidity are higher. It is impossible to achieve a balance between dimensions, and a high flash point cannot be obtained.

  In the lubricating oil composition of the present embodiment, the flash point of the naphthenic synthetic oil (a) needs to be 140 ° C. or higher. When the flash point is less than 140 ° C., a particularly high traction coefficient cannot be obtained, and a lubricating oil composition having a high flash point cannot be obtained. From the viewpoint of improving the traction coefficient and the flash point, the flash point of the naphthenic synthetic oil (a) is preferably 145 ° C. or higher, more preferably 150 ° C. or higher, further preferably 160 ° C. or higher, and the upper limit is particularly limited. However, it may be about 200 ° C. or less. In addition, in this specification, a flash point is a flash point measured by the Cleveland open method in accordance with JIS K2265-4: 2007 (How to find a flash point-Part 4: Cleveland open method).

  The naphthenic synthetic oil (a) used in the lubricating oil composition of the present embodiment is not particularly limited as long as the flash point is 140 ° C. or higher, but has a higher traction coefficient and excellent low temperature fluidity. From the viewpoint of improving the flash point, it is preferable to have a cyclic structure portion, more preferably a synthetic oil having at least one ring selected from a cyclohexane ring, a bicycloheptane ring and a bicyclooctane ring. Preferably there is. Examples of such naphthenic synthetic oil (a) include synthetic oils represented by the following general formula (1).

In general formula (1), R ¹¹ and R ¹³ each independently represent a monovalent hydrocarbon group, R ¹² represents a divalent hydrocarbon group, and X ₁₁ and X ₁₂ each independently represent a cyclohexane ring. , Bicycloheptane ring or bicyclooctane ring, p ₁₁ and p ₁₂ each independently represents an integer of 1 or more and 6 or less.

Examples of the monovalent hydrocarbon group for R ¹¹ and R ¹³ include an alkyl group, an alkenyl group, an alkadiene group, a cycloalkyl group, and an aryl group. Of these monovalent hydrocarbon groups, an alkyl group and an alkenyl group are preferable, and an alkyl group is more preferable from the viewpoint of achieving both a high traction coefficient and excellent low-temperature fluidity at a higher level and improving the flash point. preferable. These monovalent hydrocarbon groups may be linear, branched or cyclic. When the halogen atom, hydroxyl group or monovalent hydrocarbon group is a cycloalkyl group or an aryl group, an alkyl group is further added. It may have a substituent such as a group.
Further, from the same viewpoint, the carbon number of the monovalent hydrocarbon group is preferably 1 or more when the monovalent hydrocarbon group is an alkyl group, and the upper limit is preferably 12 or less, more preferably 8 or less, more preferably 4 or less, particularly preferably 2 or less, and when the monovalent hydrocarbon is an alkenyl group, it is 2 or more, preferably 3 or more, and the upper limit is preferably 12 or less, more preferably 8 or less, more preferably 4 or less.

p ₁₁ and p ₁₂ are each independently an integer of 1 or more and 6 or less, and preferably 4 as the upper limit from the viewpoint of achieving both a high traction coefficient and excellent low temperature fluidity at a higher level and improving the flash point. Below, more preferably 3 or less, and still more preferably 2 or less.

Examples of the divalent hydrocarbon group of R ¹² include those obtained by removing one hydrogen atom from the monovalent hydrocarbon group of R ¹¹ and R ¹³ to be divalent, and have a high traction coefficient and excellent performance. From the viewpoints of achieving both low temperature fluidity at a higher level and improving the flash point, an alkylene group, an alkenylene group, and more preferably an alkylene group.
Further, from the same viewpoint, the carbon number of the divalent hydrocarbon group of R ¹² is 1 or more, and the upper limit is preferably 12 or less, more preferably 8 or less, and still more preferably 4 or less.

As the ring of X ₁₁ and X ₁₂ , a bicycloheptane ring and a bicyclooctane ring are preferable from the viewpoint of achieving both a high traction coefficient and excellent low-temperature fluidity at a higher level and improving the flash point. Is more preferable.
Examples of the bicycloheptane ring include a bicyclo [2.2.1] heptane ring and a bicyclo [3.3.0] heptane ring. Examples of the bicyclooctane ring include a bicyclo [3.2.1] octane ring. And bicyclo [2.2.2] octane ring. Among these, from the viewpoint of achieving both a high traction coefficient and excellent low-temperature fluidity at a higher level and improving the flash point, a bicyclo [2.2.1] heptane ring and a bicyclo [3.3.0] A heptane ring is preferable, and a bicyclo [2.2.1] heptane ring is particularly preferable.
In addition to the monovalent hydrocarbon groups of R ¹¹ and R ¹³ , these rings may have a substituent such as a hydroxyl group or a halogen atom.

In the present embodiment, among the above, R ¹¹ and R ¹³ are each independently an alkyl group or an alkenyl group from the viewpoint of achieving both a high traction coefficient and excellent low-temperature fluidity at a higher level and improving the flash point. And a combination in which R ¹² is an alkylene group or an alkenylene group is preferred, R ¹¹ and R ¹³ are each independently an alkyl group having 1 to 4 carbon atoms, and R ¹² is an alkylene group having 1 to 4 carbon atoms. And a combination in which p ₁₁ and p ₁₂ are each independently 1 or 2 is more preferable, R ¹¹ and R ¹³ are each independently an alkyl group having 1 to 4 carbon atoms, and R ¹² is 1 or more carbon atoms. 4 is a less alkylene _{group, X 11} and _{X 12} are bicycloheptane _{ring, p 11} and _{p 12} are each independently 1 or 2 More preferably a combination ^{that, R 11} and ^{R 13} are each independently an alkyl group having 1 to 2 carbon ^{atoms, R 12} is an alkylene group having 1 to 2 carbon _{atoms, X 11} and _{X 12} is bicyclo [ 2.2.1] A heptane ring in which p ₁₁ and p ₁₂ are each independently 1 or 2 is particularly preferred.

The content of the naphthenic synthetic oil (a) based on the total composition amount is required to be 35% by mass or more and less than 80% by mass. When the content of the naphthenic synthetic oil (a) is less than 35% by mass, a high traction coefficient cannot be obtained, and a high flash point cannot be obtained. On the other hand, when the content of the naphthenic synthetic oil (a) is 80% by mass or more, excellent low temperature fluidity cannot be obtained.
The content based on the total amount of the composition of the naphthenic synthetic oil (a) is preferably 40% by mass or more from the viewpoint of achieving both a high traction coefficient and excellent low-temperature fluidity at a higher level and improving the flash point. More preferably, it is 45% by mass or more, more preferably 50% by mass or more, particularly preferably 60% by mass or more, and the upper limit is preferably 79% by mass or less, more preferably 77% by mass or less, still more preferably 75% by mass. It is as follows. In the present embodiment, the naphthenic synthetic oil (a) may be used singly or in combination of a plurality of types, and when used in combination of a plurality of types, the plurality of naphthenic synthetic oils (a). It is sufficient that the total content of is within the range of the above content.

(Branched C5-C32 Ester (b))
The lubricating oil composition of the present embodiment contains an ester (b) having a branched chain and having 5 to 32 carbon atoms (hereinafter sometimes referred to as “ester (b)”). If the lubricating oil composition of this embodiment does not contain the ester (b), particularly low temperature fluidity cannot be obtained.

  The ester (b) is not particularly limited as long as it has a branched chain, has 5 to 32 carbon atoms, and has an ester structure, but is preferably a monoester represented by the following general formula (2) And diesters represented by the following general formula (3).

In the general formula (2), R ²¹ and R ²² each independently represent a branched monovalent hydrocarbon group having 3 or more carbon atoms. In the general formula (3), R ³¹ and R ³² each independently represent a branched monovalent hydrocarbon group having 3 or more carbon atoms, and X ₃₁ represents a branched divalent hydrocarbon group having 3 or more carbon atoms. A hydrocarbon group is shown.

In the general formula (2), as the branched monovalent hydrocarbon group having 3 or more carbon atoms of R ²¹ and R ²² , among the groups exemplified as the monovalent hydrocarbon group of R ¹¹ and R ¹³ above, Examples thereof include a group having 3 or more carbon atoms and a branched shape. Of these, branched alkyl groups and alkenyl groups are preferred, and alkyl groups are more preferred from the viewpoints of achieving both a high traction coefficient and excellent low-temperature fluidity at a higher level and improving the flash point. The number of carbon atoms is preferably 4 or more, more preferably 5 or more, and further preferably 6 or more, and the upper limit is preferably 16 or less, more preferably 14 or less, and still more preferably 12 or less.

Moreover, the monovalent hydrocarbon group of R ²¹ and R ²² is a branch having a gem-dialkyl structure from the viewpoint of achieving both a high traction coefficient and excellent low-temperature fluidity at a higher level and improving the flash point. It is preferably a group having a shape. In this case, the carbon number of the alkyl group in the gem-dialkyl structure is preferably 1 or more, and the upper limit is preferably 4 or less, more preferably 3 or less, still more preferably 2 or less, and the carbon number of the two alkyl groups. May be the same or different. A particularly preferred gem-dialkyl structure is a gem-dimethyl structure in which all of the alkyl groups in the structure have 1 carbon.
Typical examples of such monovalent hydrocarbon groups for R ²¹ and R ²² include isopropyl group, 1,1-dimethylethyl group, 2,2-dimethylpropyl group, 3,3-dimethylbutyl group, 4,4-dimethylpentyl group, 5,5-dimethylhexyl group, 2,4,4-trimethylpentyl group, 3,5,5-trimethylhexyl group, 2,2,4,4,6-pentamethylheptyl Preferred examples include a group, 2,2,4,6,6-pentamethylheptyl group, 3,5,5,7,7-pentamethyloctyl group and the like. These monovalent hydrocarbon groups are merely exemplary, and in the present embodiment, the above-exemplified hydrocarbon group isomers are represented as R ²¹ and R ^22. Needless to say.

  When the ester (b) is a monoester, the carbon number is preferably 8 or more, more preferably 12 or more, from the viewpoint of achieving both a high traction coefficient and excellent low-temperature fluidity at a higher level and improving the flash point. More preferably, it is 16 or more, and the upper limit is preferably 30 or less, more preferably 25 or less, and still more preferably 21 or less.

In the general formula (3), the branched monovalent hydrocarbon group having 3 or more carbon atoms of R ³¹ and R ³² is a branched monovalent hydrocarbon group having 3 or more carbon atoms of R ²¹ and R ^22. The same thing is mentioned. Of these, branched alkyl groups and alkenyl groups are preferred, and alkyl groups are more preferred from the viewpoints of achieving both a high traction coefficient and excellent low-temperature fluidity at a higher level and improving the flash point. The upper limit of the carbon number is preferably 16 or less, more preferably 14 or less, and still more preferably 10 or less.

Examples of the divalent hydrocarbon group of X ₃₁ include those obtained by removing one hydrogen atom from the monovalent hydrocarbon group of R ³¹ and R ³² to be divalent, and have a high traction coefficient and excellent performance. From the viewpoint of achieving both low temperature fluidity at a higher level and improving the flash point, it is preferably an alkylene group, an alkenylene group, more preferably an alkylene group, and the gem-dialkyl structure as in R ²¹ and R ²² above. It is preferable to have.
From the same viewpoint, the carbon number of the divalent hydrocarbon group of X ₃₁ is preferably 4 or more, more preferably 5 or more, still more preferably 6 or more, and the upper limit is preferably 16 or less, more preferably 14 or less, more preferably 12 or less.

  When the ester (b) is a diester, the carbon number is preferably 11 or more, more preferably 12 or more, from the viewpoint of achieving both a high traction coefficient and excellent low-temperature fluidity at a higher level and improving the flash point. More preferably, it is 14 or more, and the upper limit is preferably 30 or less, more preferably 28 or less, and still more preferably 26 or less.

In the present embodiment, as the diester represented by the general formula (3), among the above, from the viewpoint of achieving both a high traction coefficient and excellent low temperature fluidity at a higher level and improving the flash point, R ³¹ and R ³² are each independently a branched alkyl group or alkenyl group having 3 to 16 carbon atoms, and a combination in which X ₃₁ is a branched alkylene group or alkenylene group having 3 to 16 carbon atoms is preferable, R ³¹ and ^{R 32} are each independently an alkyl group having 3 to 16 branched _carbon, more preferably the combination _{X 31} is an alkylene group branched having 3 to 16 carbon ^{atoms, R 31} and R ³² is a branched alkyl group having 3 to 16 carbon atoms having independently gem- dialkyl _{structure, X 31} is 3 or more carbon atoms 16 More preferably a combination a branched alkylene group below.

  The content of the ester (b) based on the total amount of the composition is preferably 10% by mass or more, more preferably 12% by mass or more, still more preferably 15% by mass or more, and particularly preferably 20% by mass or more. Is 65% by mass or less, more preferably 60% by mass or less, still more preferably 55% by mass or less, and particularly preferably 50% by mass or less. When the content of the ester (b) is within the above range, a high traction coefficient and excellent low temperature fluidity can be achieved at a higher level and the flash point can be improved. Improvement effect is obtained. Moreover, in this embodiment, the said ester (b) may be used individually or in combination of multiple types, and when using it in combination of multiple types, the total content of the multiple types of esters (b) is the above. It may be within the range of the content.

(Other additives)
The lubricating oil composition of the present embodiment contains the naphthenic synthetic oil (a) and the ester (b), and may consist of the naphthenic synthetic oil (a) and the ester (b). In addition to naphthenic synthetic oil (a) and ester (b), other additives such as viscosity index improvers, dispersants, antioxidants, extreme pressure agents, metal deactivators, antifoaming agents, etc. May be included. These other additives can be used alone or in combination of two or more.
The total content of these other additives may be appropriately determined as desired, and is not particularly limited. However, in consideration of the effect of adding the other additives, 0.1 to 20 mass based on the total amount of the composition. % Is preferable, 1 to 15% by mass is more preferable, and 5 to 13% by mass is still more preferable.

  As the viscosity index improver, for example, a polydisperse such as non-dispersed polymethacrylate or dispersed polymethacrylate having a mass average molecular weight (Mw) of preferably 500 to 1,000,000, more preferably 5,000 to 800,000. Methacrylate; Olefin copolymer having a mass average molecular weight (Mw) of preferably 800 to 300,000, preferably 10,000 to 200,000 (for example, ethylene-propylene copolymer), dispersed olefin copolymer And polymers such as styrene-based copolymers (for example, styrene-diene copolymers, styrene-isoprene copolymers);

  Examples of the dispersant include monovalent or divalent compounds represented by boron-free succinimides, boron-containing succinimides, benzylamines, boron-containing benzylamines, succinic esters, fatty acids or succinic acid. Examples include ashless dispersants such as carboxylic acid amides.

  Examples of the antioxidant include amine-based antioxidants such as diphenylamine-based antioxidants and naphthylamine-based antioxidants; monophenol-based antioxidants, diphenol-based antioxidants, hindered phenol-based antioxidants, etc. Phenolic antioxidants; molybdenum trioxides and / or molybdenum antioxidants such as molybdenum amine complexes formed by reacting molybdic acid with amine compounds; and the like.

  Extreme pressure agents include sulfurized fats and oils, sulfurized fatty acids, sulfurized esters, sulfurized olefins, dihydrocarbyl polysulfides, thiadiazole compounds, alkylthiocarbamoyl compounds, thiocarbamate compounds, etc .; phosphate esters, phosphites, acidic Phosphorus-based extreme pressure agents such as phosphate esters, acidic phosphites and their amine salts; zinc dialkylthiocarbamate (Zn-DTC), molybdenum dialkylthiocarbamate (Mo-DTC), zinc dialkyldithiophosphate (Zn) -DTP) and sulfur-phosphorus extreme pressure agents such as molybdenum dialkyldithiophosphate (Mo-DTP).

  Examples of the metal deactivator include benzotriazole, tolyltriazole, thiadiazole, and imidazole compounds, and examples of the antifoaming agent include silicone oil, fluorosilicone oil, and fluoroalkyl ether. .

(Various physical properties of lubricating oil composition)
Kinematic viscosity at 40 ° C. of the lubricating oil composition of the present embodiment is preferably ^{3 mm} 2 / s or more 50 mm ² / s or less, more preferably ^{5 mm} 2 / s or more 30 mm ² / s or less, more preferably 10 mm ² / s This is 20 mm ² / s or less. The kinematic viscosity at 100 ° C. of the lubricating oil composition of the present embodiment is preferably 0.5 mm ² / s to 15 mm ² / s, more preferably 1 mm ² / s to 10 mm ² / s, and still more preferably 1. is less than or equal to 5mm ² / s or more ^5mm 2 / s. Further, the viscosity index of the lubricating oil composition of the present embodiment is preferably 75 or more, more preferably 80 or more, and still more preferably 85 or more.
In the present specification, the kinematic viscosity and the viscosity index are values measured using a glass capillary viscometer according to JIS K2283: 2000.

The Brookfield viscosity (BF viscosity) at −40 ° C. of the lubricating oil composition of the present embodiment is preferably 15,000 mPa · s or less, more preferably 14,900 mPa · s or less, and further preferably 14,800 mPa · s or less. Particularly preferably, it is 14,750 mPa · s or less. Thus, the lubricating oil composition of this embodiment has a low Brookfield viscosity (BF viscosity) of −40 ° C. and excellent low temperature fluidity.
In this specification, the Brookfield viscosity (BF viscosity) at −40 ° C. is measured in accordance with ASTM D2983-09.

  In accordance with JIS K2265-4: 2007 of the lubricating oil composition of the present embodiment, the flash point measured by the Cleveland open method is preferably 140 ° C. or higher, more preferably 145 ° C. or higher, still more preferably 150 ° C. or higher. Yes, particularly preferably 155 ° C. or higher. Thus, the lubricating oil composition of the present embodiment has a high flash point, high flame retardancy, and high safety.

Further, the traction coefficient at 120 ° C. of the lubricating oil composition of the present embodiment is preferably 0.050 or more, more preferably 0.053 or more, and still more preferably 0.055 or more. As described above, the lubricating oil composition of the present embodiment has a high traction coefficient at 120 ° C., and has a high traction coefficient and excellent low-temperature fluidity at a higher level, and has a high flash point. It is an oil composition.
In this specification, the traction coefficient at 120 ° C. is a value measured using a traction coefficient measuring device (product name: MTM2 (Mini Traction Machine 2, manufactured by PCS Instruments), where traction coefficient at 120 ° C. The measurement conditions are as follows: First, by heating the oil tank with a heater, the oil temperature is 140 ° C., the load is 70 N, the average rolling speed is 3.8 m / s, and the traction coefficient is measured at a slip rate of 5%. did.

(Use of lubricating oil composition)
The lubricating oil composition of the present embodiment can be suitably used for continuously variable transmissions, continuously variable speed increasers and continuously variable speed reducers, especially for continuously variable transmission applications. The continuously variable transmission includes a metal belt method, a chain method, a traction drive method, and the like, but any method requires high transmission efficiency and requires a lubricating oil having a high traction coefficient. In this respect, the lubricating oil composition of the present embodiment can be suitably used for any type of continuously variable transmission, and can be particularly suitably used for a traction drive type transmission.
Further, since the lubricating oil composition of the present embodiment is excellent in traction coefficient, particularly traction coefficient at high temperature and low-temperature fluidity, for example, for continuously variable transmissions in automobiles and aircraft engine generators, especially traction drive type gear shifting. It can be suitably used as a machine fluid. In addition to the above, it can also be suitably used for continuously variable transmissions in industrial applications, such as drive units for construction machines and agricultural machines, speed increasers for wind power generation, and continuously variable speed increasers and continuously variable speed reducers.

[Method for producing lubricating oil composition]
The manufacturing method of the lubricating oil composition of the present embodiment comprises a naphthenic synthetic oil (a) having a flash point of 140 ° C. or higher and an ester (b) having 5 to 32 carbon atoms having a branched chain. It mix | blends so that content of the composition whole quantity reference | standard of oil (a) may be 35 to less than 80 mass%.

  In the method for producing a lubricating oil composition of the present embodiment, the naphthenic synthetic oil (a) having a flash point of 140 ° C. or higher and the ester having a branched chain having 5 to 32 carbon atoms (b) are the lubricants of the present embodiment. Each of the naphthenic synthetic oil (a) and ester (b) contained in the oil composition is the same as that described for the naphthenic synthetic oil (a) and ester (b). It is the same as what was demonstrated as content of the lubricating oil composition of a form. Further, in the method for producing the lubricating oil composition of the present embodiment, other additives described as components other than the naphthenic synthetic oil (a) and the ester (b), for example, components that can be included in the lubricating oil composition of the present embodiment. May be blended.

  When producing the lubricating oil composition, the blending order of the naphthenic synthetic oil (a) and the ester (b) is not particularly limited, and the ester (b) is added to the naphthenic synthetic oil (a). Alternatively, naphthenic synthetic oil (a) may be added to ester (b). Moreover, when mix | blending other additives, the various additives used as other additives mix | blended naphthenic synthetic oil (a), ester (b), or naphthenic synthetic oil (a) and ester (b). The ingredients may be blended sequentially, or the various additives may be blended in advance.

[Continuously variable transmission]
The continuously variable transmission of the present embodiment includes a naphthenic synthetic oil (a) having a flash point of 140 ° C. or higher and an ester (b) having 5 to 32 carbon atoms having a branched chain, and the naphthenic synthetic oil (a). A lubricating oil composition having a content based on the total amount of the composition of 35% by mass or more and less than 80% by mass is used.
The lubricating oil composition used in the continuously variable transmission of the present embodiment is the same as that described as the lubricating oil composition of the present embodiment.

  As the continuously variable transmission, there are a metal belt method, a chain method, a traction drive method, etc., any type of continuously variable transmission may be used, and the lubricating oil composition used has a high traction coefficient and excellent low temperature fluidity. In addition, the traction drive type continuously variable transmission is preferable from the viewpoint of more effectively utilizing this feature.

  EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not restrict | limited at all by these examples.

The properties and performance of the lubricating oil composition were measured by the following method.
(1) Kinematic viscosity Based on JISK2283: 2000, the kinematic viscosity in 40 degreeC and 100 degreeC was measured.
(2) Viscosity index (VI)
It measured based on JISK2283: 2000.
(3) Traction coefficient at 120 ° C. A traction coefficient measuring instrument (product name: MTM2 (Mini Traction Machine 2, manufactured by PCS Instruments)) is a value measured under the following measurement conditions. .
Oil temperature heating condition: 140 ° C
Load: 70N
Average rolling speed: 3.8 m / s
Slip rate: 5%
(4) Brookfield viscosity at −40 ° C. The Brookfield viscosity (BF viscosity) at −40 ° C. was measured according to ASTM D2983-09. If it is 15,000 mPa · s or less, it is acceptable.
(5) Flash point Measured by the Cleveland open method according to JIS K2265-4: 2007 (How to determine the flash point-Part 4: Cleveland open method). If it is 140 degreeC or more, it is a pass.

(Production of lubricating oil compositions of Examples 1 to 5 and Comparative Examples 1 to 5)
A lubricating oil composition was prepared by blending according to the blending formulation shown in Table 1 below. Table 1 shows the evaluation results of the properties and performances measured by the above methods for the obtained lubricating oil compositions.

  The naphthenic synthetic oils, esters 1 to 4, and longifolene shown in Table 1 used in this example are represented by the following chemical formulas.

-Naphthenic synthetic oil: In the general formula (1), R ¹¹ and R ¹³ are methyl groups, R ¹² is a methylene group, and X ₁₁ and X ₁₂ are bicyclo [2.2.1] heptane rings , P ₁₁ is 2 and p ₁₂ is 1.
Ester 1: A monoester in which R ²¹ is a 3,5,5-trimethylhexyl group and R ²² is a 2,4,4-trimethylpentyl group in the general formula (2).
Ester 2: In general formula (3), R ³¹ and R ³² are isopropyl groups, and X ₃₁ is a 2,2,4-trimethylpentyl-1,3-diyl group.
Ester 3: In general formula (3), R ³¹ and R ³² are 2,4,4-trimethylpentyl groups and X ₃₁ is a 3-methylpentyl-1,5-diyl group.
Ester 4: In the general formula (3), R ³¹ and R ³² are 2,4,4-trimethylpentyl groups, and X ₃₁ is a 2,2-dimethylpropyl-1,3-diyl group. .
Additive: Viscosity index improver (in Examples 1 to 4 and Comparative Examples 1 to 5 containing 1.5% by mass as the content based on the total amount of the composition), other dispersant (succinimide), antioxidant Agent, extreme pressure agent, metal deactivator, and antifoaming agent

From the results in Table 1, the lubricating oil composition of this embodiment has a traction coefficient of 0.050 or more, a Brookfield viscosity at −40 ° C. of 15,000 mPa · s or less, and a flash point. Since it is 140 degreeC or more, while confirming that a high traction coefficient and the outstanding low-temperature fluidity were compatible in a higher dimension, it was confirmed that it has a high flash point.
On the other hand, the lubricating oil composition of Comparative Example 1 in which the content of the naphthenic synthetic oil (a) is less than 35% by mass and does not contain the ester (b) has a low flash point of 120 ° C. The lubricating oil composition of Comparative Example 2 in which the content of the synthetic oil (a) is 80% by mass or more has a very large Brookfield viscosity at −40 ° C. of 60,000 mPa · s or more and is inferior in low-temperature fluidity. It was confirmed. In addition, the lubricating oil compositions of Comparative Examples 3 to 5 containing no naphthenic synthetic oil (a) had a traction coefficient as low as less than 0.050 and could not be said to have a high traction coefficient.

Claims (15)

  It contains a naphthenic synthetic oil (a) having a flash point of 140 ° C. or higher and an ester (b) having 5 to 32 carbon atoms having a branched chain, and the content of the naphthenic synthetic oil (a) based on the total composition is 35 A lubricating oil composition having a mass percentage of less than 80 mass%.   The lubricating oil composition according to claim 1, wherein the naphthenic synthetic oil (a) is a synthetic oil having at least one ring selected from a cyclohexane ring, a bicycloheptane ring and a bicyclooctane ring. The lubricating oil composition according to claim 1, wherein the naphthenic synthetic oil (a) is a synthetic oil represented by the following general formula (1).

(In the general formula (1), R ¹¹ and R ¹³ each independently represent a monovalent hydrocarbon group, R ¹² represents a divalent hydrocarbon group, and X ₁₁ and X ₁₂ each independently represent cyclohexane. A ring, a bicycloheptane ring or a bicyclooctane ring, and p ₁₁ and p ₁₂ each independently represents an integer of 1 to 6. In the general formula (1), X ₁₁ and X ₁₂ are each independently a cyclohexane ring, a bicyclo [2.2.1] heptane ring, a bicyclo [3.3.0] heptane ring, or a bicyclo [3.2. 1) The lubricating oil composition according to claim 3, which is an octane ring or a bicyclo [2.2.2] octane ring. The lubricating oil composition according to claim 3 or 4, wherein, in the general formula (1), R ¹¹ and R ¹³ are each independently an alkyl group or an alkenyl group, and R ¹² is an alkylene group or an alkenylene group. In the general formula (1), R ¹¹ and R ¹³ are each independently an alkyl group having 1 to 4 carbon atoms, R ¹² is an alkylene group having 1 to 4 carbon atoms, and p ₁₁ and p ₁₂ are The lubricating oil composition according to any one of claims 3 to 5, which is independently 1 or 2. The ester (b) is at least one ester selected from a monoester represented by the following general formula (2) and a diester represented by the following general formula (3). The lubricating oil composition described in 1.

(In General Formula (2), R ²¹ and R ²² each independently represent a branched monovalent hydrocarbon group having 3 or more carbon atoms. In General Formula (3), R ³¹ and R ³² are And each independently represents a branched monovalent hydrocarbon group having 3 or more carbon atoms, and X ₃₁ represents a branched divalent hydrocarbon group having 3 or more carbon atoms.) The lubricating oil composition according to claim 7, wherein in the general formula (2), R ²¹ and R ²² are each independently a branched alkyl group or alkenyl group having 3 to 16 carbon atoms. In the general formula (3), R ³¹ and R ³² are each independently a branched alkyl group or alkenyl group having 3 to 16 carbon atoms, and X ₃₁ is a branched alkylene group having 3 to 16 carbon atoms. Or it is an alkenylene group, The lubricating oil composition of any one of Claim 7 characterized by the above-mentioned.   The lubricating oil composition according to any one of claims 1 to 9, wherein the content of the ester (b) based on the total composition is 10% by mass or more and 65% by mass or less.   The lubricating oil composition according to any one of claims 1 to 10, wherein the Brookfield viscosity at -40 ° C measured in accordance with ASTM D2983-09 is 15,000 mPa · s or less.   The lubricating oil composition according to any one of claims 1 to 11, wherein the flash point measured by the Cleveland open method is 140 ° C or higher in accordance with JIS K2265-4: 2007.   The lubricating oil composition according to any one of claims 1 to 12, which is used in a traction drive type transmission.   A naphthenic synthetic oil (a) having a flash point of 140 ° C. or higher and an ester (b) having 5 to 32 carbon atoms having a branched chain are contained on the basis of the total composition of the naphthenic synthetic oil (a). The manufacturing method of the lubricating oil composition mix | blended so that it may become 35 to 80 mass%.   It contains a naphthenic synthetic oil (a) having a flash point of 140 ° C. or higher and an ester (b) having 5 to 32 carbon atoms having a branched chain, and the content of the naphthenic synthetic oil (a) based on the total composition is 35 A continuously variable transmission in which a lubricating oil composition having a mass percent of less than 80 mass percent is used.